French Huguenot Jean Calas, who had been wrongly convicted of killing his son, dies after being tortured by authorities; the event inspired Voltaire to begin a campaign for religious tolerance and legal reform.

The Huguenots are a religious group of French Protestants who held to the Reformed (Calvinist) tradition of Protestantism. The term, which may be derived from the name of a Swiss political leader, the Genevan burgomaster Besançon Hugues, was in common use by the mid-16th century. Huguenot was frequently used in reference to those of the Reformed Church of France from the time of the Protestant Reformation. By contrast, the Protestant populations of eastern France, in Alsace, Moselle, and Montbéliard, were mainly Lutherans.

Jean Calas was a merchant living in Toulouse, France, who was tried, judicially tortured, and executed for the murder of his son, despite his protestations of innocence. Calas was a Protestant in an officially Catholic society. Doubts about his guilt were raised by opponents of the Catholic Church and he was exonerated in 1764. In France, he became a symbolic victim of religious intolerance, along with François-Jean de la Barre and Pierre-Paul Sirven.

François-Marie Arouet, known by his nom de plume Voltaire, was a French Enlightenment writer, philosopher (philosophe), satirist, and historian. Famous for his wit and his criticism of Christianity and of slavery, Voltaire was an advocate of freedom of speech, freedom of religion, and separation of church and state.

March 10 is the 69th day of the year in the Gregorian calendar; 296 days remain until the end of the year.